Electromagnetic switch



April 26, 1932.. LUCAS 855,804

ELECTROMAGNETIC SWITCH Filed Nov. 8, 1928 INVENTOI? ATTORNEY Patented Apr. 26, 1932 UNITED STATES PATENT OFFICE WILLIAM BATES LUCAS, OF EAST ORANGE, NEW JERSEY, ASSIGNOB TO OTIS, ELEVATOR COMPANY, OF NEW YORK,

N. Y., A CORPORATION OF NEW JERSEY mno'raomeunrrc swrrcn Application filed November 8, 1928. Serial No. 817,977.

This invention relates to electromagnetic devices and particularly to electromagnetic switches.

This application is a continuation in part of application Serial No. 41,098, filed July 2,.

One feature of the invention is the provision of an electromagnetic switch having two operative positions in which a single electromagnet is utilized to effect the operation of the switch from either operative position to the other.

Another feature of the invention is the provision of an electromagnetic switch of the above character which is economical in the consumption of current.

Still another feature of the invention is the provision of an electromagnetic switch of the above character in which the inertia of its armature is utilized to assist the operation of the switch.

A fourth feature of the invention is the provision of an electromagnetic switch which is of rugged construction, cheapto manufacture, and small and compact for the duty required.

Other features and advantages will become apparent from the specification, taken in connection with the accompanying drawings wherein several embodiments of the invention are illustrated.

In the drawings Figure l diagrammatically shows an electromagnetically controlled switch, together with operating circuits therefor:

Figure 2 is a front elevation of form of switch;

Figures 3 and 4 are side elevations thereof, with parts broken away to illustrate certain features of construction;

Figure 5 diagrammatically shows the switch of Figures 2, 3' and 4, together with one arrangement of circuits therefor;

Figure 6 is similar to Figure 5 with an other arrangement of circuits; and

Figure 7 is a diagrammatic representation of a modified formof the switch of Figures 2. 3 and 4, together with an arrangement of circuits therefor. i

Referring to Figure a preferred 1, there are shown two circuit sections 6 and 7 which are to be connected or disconnected by switch 21. This switch comprises a lever 26, pivotally supported as at 27 and arranged so that one end thereof makes sliding frictional contact with the terminals or contacts 28 and 29 alternately as the switch lever is swung to and fro about its support. Contact 29 is connected to section 6 by means of conductor 32 and switch lever 26 is connected to section 7 by means of conductors 24 and 24, so that the two sections are connected when the switch lever is swung to the right and engages contact 29, and are disconnected when the switch lever is swung to the left and engages contact 28. Beyond its pivot point, the switch lever is provided with an armature 25. An electromagnet including a coil 23 wound about a core 22 is positioned below the armature and is adapted to cooperate therewith to cause the swinging of the switch lever from either position into the other position. The circuit for the coil 23 of the electromagnet may be controlled at any desired remote point, as by means of push buttons '30 and 31. The electromagnet is positioned so that the centerline of the core 22 is in alignment with the centerline of the armature when the switch lever is midway between contacts 28 and 29. The push button is connected on the one hand to contact 28 by means of conductor 12, and on the other by conductor 33 to one terminal of a source of electrical energy 13, as a battery. The other terminal of the battery is connected by conductor 11 to a terminal of the coil 23, the other terminal of which is connected to the switch lever by conductor 24'. One lead from the push button 31 is connected to the circuitsection 6, while the other lead is connected to the conductor 33. The push buttons are preferably of the normally-open self-restoring type, although other types of circuit-closing devices may be used.

In operation, let'it be assumed that switch lever 26 is in engagement with contact 28, as shown in the full outline, thereby maintaining sections 6 and 7 disconnected, and that push button 30 is depressed. This operation of the button 30 completes a circuit for coil 23 which may be traced, from the lower terminal of the battery 13, by way of conductor 33, push button 30, conductor 12, contact 28, switch lever 26, conductor 24, coil 23, to the upper terminal of the battery. The coil 23 is thus ener ized, and the resulting ma netic attraction etween the armature 25 an core 22 tends to bring the centerline of the armature into alignment with the centerline of the core. The switch lever 26 is thus moved clockwise about its pivot, disengaging contact 28, to thereby break the circuit previousl traced and deenergize the coil 23. Due to tlie inertia of the armature, however, its motion continues until the switch lever is in the position shown in dotted outline, when it engages with contact 29 and ceases its motion. The sections 6 and 7 are then connected.

Let it now be assumed that, while switch lever 26 is in engagement with contact 29, push button 31 is depressed. This operation of the button 31 completes a circuit for'coil 23 which may be traced from the lower terminal of the battery 13 by way of conductor 33, push button 31, conductor 6, conductor 32, contact 29, switch lever 26, conductor 24, coil 23, to the upper terminal of the battery. The coil 23 isthus energized, and the armature is moved counterclockwise by the resulting magnetic attraction tending to align the centerline of the armature with the centerline of the core. This movement of the armature disengages switch lever 26 from contact 29, thereby breaking the circuit last traced and deenergizing coil 23. Due to the inertia of the armature, however, its motion continues until the switch lever is in the original position as shown in full outline, when it engages with contact 28 and ceases its motion. This causes sections 6 and 7 to be disconnected. F

It is to be noted that if either push button is maintained closed for any reason after having been once depressed to control the switch, nothing further happens and no energy from the battery, beyond the initial impulse to control the switch, isconsumed.

Figures 2 to 4 inclusive illustrate a preferred form of switch. The various parts are mounted on a support 35, which may be a copper-plated sheet steel stamping. This support has stepped fastening ends 38, two contact supporting portions 36 and 37, and a connecting cross-piece 39 with extensions 40 and 41,-.the former for a front bearing support and the latter for a coil support. In addition, 'coil support 41 has a lip extension 42 for a rear bearing support. The legs of a U-shaped armature 43 are adjacent the front and rear bearing supports, and are pivotally mounted thereon by the long pin 44 which extends between the two bearing supports and through an oversize hole (not shown) in the coil support. The front leg of the armature engages with the edges of the contact-supporting portions 36 and 37 alternately, as the armature is swung to and fro, which portions thereby function as stops to limit the motion of the armature. Operating coil 46 is secured -to the coil support 41 so that the end of its core 47 is adapted to attract the voke of the armature from either extreme position to a position midway between the two extremes. The terminals for the coil are indicated by reference character 5 Mounted upon contact-supporting portion 36 of stamping 35 by the machine screws 50 is the metallic contact plate 51 to which is affixed the contact 52. Similarly mountedupon contact-supporting portion 37 is the metallic contact plate 53 to which is afiixed the contact 54. Both contact strips are insulated from the sheet steel stamping by means of the insulating strips 55 which are placed on both sides of the contact-supporting portions of the stamping, and both contact strips have terminal-connecting portions 56 to which leads may be attached, as by soldering.

A metallic switch lever 58 is pivotally sup ported upon pin 44 between extensions 40 and 41 and with its lower surface below the pin. This lower surface has afiixed thereto a contact 62 which engages with the stationary contact 52 when the switch lever is in one extreme position, and also a contact 64 which engages with the stationary contact 54 when the switclrlever' is in the other extreme position. A portion 59 of the switch lever extends above the pin and rotatably supports a toggle link 60, the outer end of which extends through an opening 61 in the yoke of the armature. A spring 63 under compression surrounds the toggle link, and presses at one end against the underside of the armature yoke and at the other end against a shoulder on the toggle link. Washers 65 may be used to separate the moving parts from the stationary parts.

It is to be noted that when the parts are in the position as shown in Figure 3, a torque resulting from the force of the spring and the'displacement of the toggle link pivot out of the plane through pin 44 and opening 61, hereinafter referred armature, urges the switch lever clockwise and the armature counterclockwise, thereby maintaining contacts 52 and 62 in engagement, and the frontleg of the armature against the stopping edge of portion 36.

From the positions of the parts asshown in Figure 3, let the armature be moved clockwise until it is in a position where the yoke is a small distance past the center of the core, that is, until the armature has reached and passed a little beyond its mid-position. This movement further compresses the spring, but reduces the displacement of the toggle link pivot from the to as the plane of the plane of the armature until' at the above posltion it is substantially zero,

At the termination of the movements,

- are represented diagrammatically.

when the torque also is substantiallyv zero. Further clockwise movement of the armature increases the displacement of the toggle link pivot from the plane of the armature, but in the opposite direction, so that the torque is reversed and the switch lever is urged counter clockwise, which moves accordingly, thereby disengaging contacts 52 and 62 and engaging contacts 54and 64. In addition, the spring urges the armature over to the extreme clockwise position with the front armature leg against the stopping edge of portion ti'li'.

t e parts are as shown in Figure 4.

The operation of the parts in the reverse direction bein analogous to the operation above describec l, it is for conciseness omitted. It is to be notedthat in either case, however, the armature need only be moved to a little past the mid-position, from which point the completion of the movements of the parts of the switch is eflected automatically. It is also to be noted that after each operation of the switch the parts are maintained in their new positions by the action of spring Figure 5 illustrates one arrangement of the control circuits for the switch of Figures 2, 3 and 4 which is'similar in many respects to the wiring diagram shown in Figure 1. For simplicity, various parts of the switch Similarly as with Figure 1, there are two circuit sections 66 and 7 O which are to be connected or disconnected. One section 66 is connected by conductor67 to switch lever 58, which,

' in the embodiment illustrated, is accomplished by connecting to the sheet steel stamping as' ground. If desired, the conductor may be appropriately secured directly to the contact arm. The other circuit section is connected-to one of the fixed contacts, as 52. One end of. the coil 46 is connected through a source of electrical energy 68, as a. battery, to conductor 67 ,and the other end of the coil is connected to aconductor 69 to'which is connected one terminal of each of two push buttons 71 and 7'2. The second terminal of push button 72 is connected to fixed contact 52, and the second terminal of push button 71 is connected to the fixed contact 54.

The two circuit sections 66 and .70 are shown disconnected. If push button 71 is depressed, a circuit through the operating coil 46 is completed. This circuit may be traced from the left-hand terminal of the battery 13, by way of conductor 67, switch lever 58. contacts 64 and 54, push button 71. conductor 69, through the operating coil, to the right-hand terminal of the battery. The energization of the operating coil results in the attraction of armature 43 from its extreme position to the mid-position. Due to its inertia, however, it does not stop in position,

mid-position but continues on past. The spring then operates as previously described to insure the movement of the armature t0 the other extreme position, to disengage contacts 54 and 64, to engage contacts 52 and 62 and to maintain the parts in these new positions. The circuit through push button 71 is therefore broken andvthe operating coil deenergized, thereby permitting the contacts 52 and 62 to remain engaged and to prevent further consumption of controlling energy, even though the push button is maintained depressed. Since contacts 52 and 62 are in engagement, the two circuit sections are connected.

Ifpush button 72 is now depressed, a circuit through the operating coil 46 is com pleted. This circuit may be traced from the left-hand terminal of the battery 13, by way of conductor 67, switch lever 58, contacts 62 and 52, push button 72, conductor 69, through the operating coil, to the right-hand terminal of the battery. The resulting energization of the operating coil attracts the armature to the mid-position. Due to its inertia, however, it does not stop in midbut continues on past, when the spring operates in the manner previously described to insure the movement of the armature to the extreme position, to disengage contacts 52 and 62, to engage contacts 54 and 64, and to maintain the parts in these new positions'.-- The circuit through push button 72 is accordingly broken, the operating coil is deenergized, and the parts are in a position to be again controlled by an operation of push button 71.

It is to be noted that in Figure 5, the battery 68 supplies the energy to control the switch, and that this source of energy is independent of any source that may exist in the circuit of which sections 66 and 70 are a part. In Figure 6 is shown a rearrangement of Figure 5 in which the operation of the switch is the same, and is therefore not repeated, but in which the energy tooperate the switch is derived from a source 74 which is also the source of supply for the main circuit. In this rearrangement the main circuit with a load 75 connected thereto and supplied by the source 7'4 is closed and opened by the en gagement and'disengagement of contacts 52 and 62. The lead from the relay coil to the power supply is in this instance connected to the main circuit between the load and the source of supply, as at 76.

Switches of different designs may be made which operate in a substantially similar manner. Illustrative of this is the latching switch and circuits therefore diagrammatically shown by Figure 7. Core 81 of operating coil attracts the armature 83, which may be U-shaped similar to armature 43, and which is pivoted as at 85. A switch lever 158 with contacts 162 and 164 at either end is pivotally supported as at 84 so that in one position of the switch lever contact 164 is engaged with a stationary contact 154, and in another position contact 162 is engaged with a stationary contact 152. A rod'86 has one end secured tothe armature 83 and the other end secured by a spring 87 to a fixed pin 88 positioned below the pivot 85. The armature is also provided with extensions 90 and 91 for cooperating with the armsof switch lever 158. The switch lever has also secured thereto a V-shaped portion 92 which cooperates with a similarly shaped butinverted end 93 of a rigidly supported spring 94. The connections between coil 80, battery 168, push buttons 171 and 172, contacts 152 and 154, switch leverl58 and circuit sections 166 and 170 may be similar as in Figure 5.

In operation, let it be assumed that the parts are initially in the positions as shown in Figure 7. In this position armature 83 is urged clockwise by the action of spring 87 but is maintained in the position shown by the engagement of extension 91 with the switch lever 158 which can move no further clockwise due to the engagement of contacts 164 and 154. If push button 171 is depressed, a circuit from the battery through the coil is completed similarly as described with reference to Figure 5, and armature 83 is attracted toward core end 81 and accordingly the armature moves counterclockwise against the action of spring 87. Extension 91 immediately disengages with switch lever 158, but contacts 164 and 154 are maintained engaged by the action of the spring end 93 against V-shaped portion 92 secured to the switch arm. Acquiring velocity, the armature moves toward the core, but due to its inertia, it does not'stop opposite the core but continues on past. Spring 87 now urges the armature counterclockwise. Extension 90, which has become engaged with the switch lever, transmits the counterclockwise movement of the armature to the switch lever, which thereby moves to disengage contacts 164 and 154 and de'energize the coil 80. Unimpeded by attractive force of the core end for the armature, spring 87 then moves the armature and the switch lever to the counterclockwise limit at which position contacts 162 and .152 are engaged and circuit sections 166 and 170 are connected. During the movement of the switch lever, spring end 93 rides from one side of 'V- shaped portion 92 to the other. With contacts 162 and 152 engaged, the switch lever may be returned to its initial position by the operation of push button 172. The resulting operation of the switch parts is similar to their operation in the first instance and accordingly is not described. Circuit sections 166 and 170 may therefore be connected or disconnected by the depression of of said operating coil to push buttons 171 and 172, respectively. 7

It is to be noted in conjunction with the switches and connections shown in Figures 2 to 7 inclusive that if both of the controlling push buttons are depressed simulta neous that is, if the individual controlling devices are operated together, the armature will rapidly oscillate between its two extreme positions. It is thus apparent that this device may also be used to mechanically operate a bell or other instrument from either the switch lever or the armature, not only to obtain, singlestrokes or individual movements but also a rapid succession of strokes or movements"'with only one actuation of the controlling devices.

As many changes could bemade in the ab ove construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all mat ter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What isclaimed is 1. Electromagnetic switching mechanism comprising, in combination; a single operating coil; a movable armature cooperating with said coil, said armature being pivotally supported so that said armature swings across the free core end of said operating coil; limit stops cooperating with said armature to con- -fine the movement thereof to a small are at the approximate mid-length of which is located said free core end of said operating coil; a switch arm pivotally supported so that it rotates in a plane parallel to the plane (or planes) in which oscillates the radial portion (or portions) of said armature; two station ary contacts mounted in the path of movement of said switch arm for engagement by said switch arm and to form stops for confining the movement of said switch arm to an oscillatory action in which the engagement of said switch arm with one of said contacts determines the limit of movement of the switch arm in one direction and the engagement of said switch arm contacts determines the limit of movement of the switch arm in the other direction; a circuit connecting said switch arm to one terminal of said operating coil; two additional circuits, one connecting one of said stationmy contacts, and the second additional circuit connecting said second terminal of said operthe second terminal with the other of said ating coil to the other of said stationary con- I support; and compressible means connecting said projection on said switch arm with said armature at a point removed from the pivotal point of said armature for malntaming, when said operating coil is in'deenergized COIldlsaid armature has moved,

' ing coil,

tionary contact, and,

. of the armature to provide stored in said compression tion, said switch arm in engagement with one or the other of said stationary contacts while said armature is in one or the other, respectively, of its limit positions, and for causing upon the energization of the operatmg coil as a result of the closure of the circuit-closing means associated with the stationary contact engaged by said switch arm and while said, armature is attracted toward the free core end of said operating coil against the compression effect of said compressible means, the continued engagement of said switch arm with such stationary contact to maintain the circuit for the operating coil complete, until as a result of its inertia, past the free core end of said operatand for thereupon causing the disengagement of saidswitch arm with such staas a result of the energy means, causing the engagement of said switch arm with the other stationary contact and the continued movement of said armature until it reaches its other limit position.

2. Switching mechanism comprising; a frame; a pivot pin supported by said frame; a U-shaped armature pivotally mounted on said pin, said pin extending through the legs an axis parallel to the yoke thereof; stops to limit the move-' ment of said armature in each direction about its pivot; a magnet core supported by said frame so that, with the armature midway between its limiting positions, the core is in alignment with the armature and has its core face adjacent the armature yoke; a coil on said core a lever member pivotally supported on said pivot pin at a point substantially equidistant from its ends; a contact at each end of said movable lever member; a stationary contact adapted to cooperate with each of said movable contacts and arranged so that in one position of the levermember one of the stationary contacts engages one of the movable contacts and provides a stop for the lever member in one direction, and so that in another position of the lever member the other stationary contact engages the other movable contact and provides a stop for the lever member in the other direction; a circuit for energizing said magnet coil when said lever member is in one contact-engaging position, said circuit including the contacts which are in engagement when said lever member is in said one contact-engaging posit1on; a circuit for I said armature; and a spring positioned on\ said link having one of its ends bearing against a seat formed on said link and the other end bearing against the yoke of said armature, said spring normally acting through the toggle formed by said link and said arm to urge the lever member and the armature in opposite directions to retain the lever member in either of its. contact-engaging positions and the armature in its limiting position opposite thereto, but, upon energization of said coil to attract said armature, yielding to permit movement of said armature from either of its positions toward said core face while retaining said lever member in its initial position to maintain the corresponding energizing circuit for the magnet coil unbroken, an after the armature reaches a point where its plane coincides with the arm of said lever, acting through said toggle to cause movement of said lever member into its other contact-engaging position and of said armature into its other limiting position, said lever member, upon such movement, breaking the circuit for said magnet coil by which said coil was-energized, and causing the deenergization of said magnet coil.

In testimony whereof, I have signed my name to this specification. 

